Water-soluble pouches have recently become popular. This product provides the consumer with a unitary dose of detergent, conveniently packaged in a pouch, thereby reducing the necessary contact with the hand of the user. Such water-soluble pouches are made using a typically transparent or translucent film, allowing the user to see the product within the pouch. This affords the manufacturer the opportunity to design the aesthetics of the product to the consumer's preferences, demonstrating differences and benefits. Multi-compartment pouches bring further advantages. For example, the manufacturer is able to formulate, otherwise, incompatible ingredients into a single product or create a sequential release product to meet cleaning, softening or ingredient compatibility demands.
The Applicant has learnt that consumers connote opaque, preferably white, compositions with improved cleaning and care. Hence the Applicant has made efforts to design a water-soluble pouch product wherein at least a first compartment comprises an opaque, and substantially white, liquid composition.
Moreover, when designing a multi-compartment pouch, the Applicant has learnt that a consumer, in their acceptance of water-soluble pouch products, need to understand the individual benefit each compartment brings. It is therefore particularly desirable to formulate the compositions within the compartments such that they appear visibly different. Hence the detergent manufacturer may add different colouring agents to each composition. However different colours in such close proximity over shadow one another, clash or are simply not seen because of an over riding effect of another. It is preferred, therefore, that one compartment comprises a composition that is generally white or black, to create a background on which another colour can be presented.
A white product can be achieved by the addition of an opacifier to the composition. However the Applicants have found that whilst opacifier produces a white product at the point of manufacture, the product rapidly degrades. The degraded product takes on a yellow hue and continues to become more yellow on ageing.
One solution to this problem is to increase the level of opacifier. Yellowing of the product is not prevented, but the level of opacifier could provide sufficient whiteness for the average shelf life of the product. The Applicants have found however that, at the level of opacifier necessary to achieve this effect, the opacifier has a negative impact on water-soluble film dissolution, residue formation and spotting on fabrics being washed.
In addressing this problem, the Applicant has found that by combining opacifier with antioxidant, the yellowing effect of the opacifier, can be controlled. This solution not only prevents or reduces the discolouration, but also means that the manufacturer does not need to employ excessive amounts of opacifier.